Not sure why the MiniWireless come with duemilanove , but there are no issue at puting OptiBoot or DualOptiboot on it. I upgraded all of mine to the dDalOptiboot to support OTA update without any issue.

The bootloader fit within 2K and therefore, except if you need more than 30K for your sketches, this is suitable out of the box. The only point to take care of is about the fuses, to accommodate the bootloader size and the boot sequence.

I've been able to make some progress with LowPowerLab wireless programming solution, but it need some polishing before publish.

In addition to the Flash CS pin change between the boards, I've struggled a lot because, it seem the erase page doesn't properly work and some of the SPI communication doesn' t work so well. The chip identification almost always return 00.